German Patent Application No. 195 34 445 refers to an outwardly opening fuel injector which has a conical sealing seat. The valve needle has a central bore which leads into a pressure chamber upstream from the sealing seat. An actuator, embodied as a piezoelectric actuator, is braced against a nozzle body on the one side and against a pressure shoulder, which is connected to the valve needle by force-locking, on the other side. A restoring spring keeps the valve needle in a closing position. In response to the actuator being energized, the valve needle, due to the actuator's longitudinal extension, is opened against the closing force of the restoring spring and fuel is spray-discharged.
One of the disadvantages of the fuel injector referred to in this reference is, in particular, that the fuel jet injected into the combustion chamber of the internal combustion engine has a conical shape and a particular opening angle α. An injection at different opening angles α, which takes into account, for example, the various demands on the form of the mixture cloud in the partial load and full load range, is not possible.